1. Field of the Invention
The present invention relates to modular ventilation fan assemblies for electronics enclosures, and more particularly to pivoting ejectors and handles for such assemblies.
2. Description of Related Art
Modular ventilation fan assemblies, sometimes called fan tray assemblies (or more briefly, xe2x80x9cfan traysxe2x80x9d) are used for mounting ventilation fans to electronics enclosures, such as computer enclosures. Conductive enclosures are used to contain electromagnetic interference (EMI) generated by electronic equipment, and ventilation fans are often used for thermal control of their enclosed interior spaces. The fan tray provides for convenient mounting of one or more ventilation fans to the electronics enclosure while maintaining the EMI-shielding integrity of the enclosure. The fan tray may also provide a convenient location for mounting a control circuit for the ventilation fan or fans in the fan tray.
The ventilation fan itself is usually a modular unit that includes a rotor and a motor encased in a plastic housing. As such, it does not provide EMI shielding and may itself be a source of EMI. Fan trays therefore typically provide metal grills on opposite sides of the fan for purposes of safety, while allowing for the passage of air through the fan tray. At the same time, the metal grills and sheet metal walls of the fan tray maintain electromagnetic isolation for the interior of the electronics enclosure and serve as part of the wall thereof.
In some applications, the fan tray has an interface connector at an end of the fan tray. The interface connector may be a socket-type connector that is oriented away from the fan tray to connect with a corresponding pin-type connector mounted to the electronics enclosure. To assemble the fan tray to the electronic enclosure, the fan tray is slid into a port or opening of the enclosure until the interface connector engages the corresponding connector in the electronics enclosure. The fan tray is then retained in the enclosure by the surrounding walls of the port or opening in the enclosure, in cooperation with the frictional engagement of the interface connector to the connector of the enclosure.
To assist with removal of the fan tray from the electronics enclosure, a pivoting grab handle may be provided at an end of the fan tray opposite to the interface connector. When the fan tray is in use, the pivoting grab handle may be folded out of the way against the end of the fan tray. It may then be lifted away from the end of the fan tray, and used as a pull tab to break the frictional engagement of the connectors and extract the fan tray from the electronics enclosure. Such handles have the advantage of being relatively simple to construct and operate, while also being compact and unobtrusive.
Such pivoting handles, however, are also subject to certain disadvantages. One disadvantage is that they require the use of a screw, bolt, rivet, or like fastener to attach the handle to the fan tray and provide a pivot axis, thereby requiring additional inventory for manufacturing and additional operations for assembly. A second disadvantage is that they are somewhat difficult to grasp when they are folded against the end of the fan tray. Still another disadvantage is that no additional leverage is provided by the pivoting action to assist with disengagement of the interface connector, because the handle is simply used as a pull tab. To remove a fan tray using a prior art handle, the user is required to pull with a high initial force to disengage the connectors, and to quickly reduce the pulling force after disengagement occurs to avoid over-accelerating the fan tray. Such manipulations are more cumbersome than is generally desirable.
The present invention provides a snap-in fan tray ejector and handle that overcomes the limitations of prior art pivoting handles, while retaining their advantages.
Like prior art handles, the ejector and handle of the present invention is compact and inexpensive to make. It may be stamped from sheet metal stock, and when not in use, be made to fold against an end of a fan tray.
In addition, the ejector and handle incorporates several novel features that together provide reduced manufacturing and assembly costs, and greater utility in operation. A need for a fastener such as a screw, bolt, or rivet to attach the ejector and handle to a fan tray is eliminated by configuring the ejector and handle to snap into recesses typically provided by the mounting holes of ventilation fan frames. In an embodiment of the invention, the snap-in action is provided by protruding bushings placed on opposing spring tabs that extend from a central pivot arm of the handle. The protruding bushings may be integrally formed in the sheet metal of the handle by half-shearing the metal using a pin-shaped tool.
The ejector and handle also incorporates a novel bumped edge at an end of the central pivot arm adjacent to the spring tabs. When the ejector and handle is lifted away from the end of the fan tray, the bumped edge engages an adjacent part of the computer housing, providing a fulcrum against which the central pivot arm of the handle can be used as a lever. Thus, leverage can be attained to break the engagement of the interface connector over a relatively short working distance. After the engagement has been broken, the ejector and handle no longer functions as a lever, and may instead be used as a pull tab at a relatively low force level to remove the disengaged fan tray.
The handle may additionally be configured to include an offset portion at an end of the central pivot arm distal from the spring tabs. The offset portion facilitates grasping when the ejector and handle is folded against the end of the fan tray, increasing convenience for the user.
A more complete understanding of the snap-in fan tray ejector and handle will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment. Reference will be made to the appended sheets of drawings which will first be described briefly.